RT Journal Article
A1 Marek Parfieniuk
AD Department of Digital Media and Computer Graphics, Faculty of Computer Science, Bialystok University of Technology, Wiejska 45A, Bialystok 15-351, Poland
A1 Maxim Vashkevich
AD Department of Computer Engineering, The Belarusian State University of Informatics and Radioelectronics, P. Brovky 6, Minsk 220027, Belarus
A1 Alexander Petrovsky
AD Department of Digital Media and Computer Graphics, Faculty of Computer Science, Bialystok University of Technology, Wiejska 45A, Bialystok 15-351, Poland

PB iet
T1 Short-critical-path and structurally orthogonal scaled CORDIC-based approximations of the eight-point discrete cosine transform
JN IET Circuits, Devices & Systems
VO 7
IS 3
SP 150
OP 158
AB A family of multiplierless transforms is presented that approximate the eight-point type-II discrete cosine transform (DCT) as accurately as the state-of-the-art scaled DCT schemes, but having 14–17% shorter critical paths (1/6 or 1/7 less adders). Compared to the existing solutions that use the coordinate rotation digital computer (CORDIC) algorithm, the advantage of higher throughput is accompanied by saving additions. Only some lifting-based BinDCT schemes require less adders in total, in spite of longer critical paths. The transforms have been derived from the fast Loeffler's algorithm by replacing the rotation stage with unfolded CORDIC iterations, which have been arranged so that two rotation approximations use the same scaling. This is equivalent to imposing structural orthogonality (losslessness) on a system, from which the scaling can then be extracted so as to shorten the critical path. Supporting ideas are a notation for more conveniently describing CORDIC circuits, and an angle conversion that allows rotations to be approximated using an extended set of CORDIC circuits. The research results have been validated by field programmable gate array-based hardware design experiments and by usability tests based on a software JPEG codec.
K1 CORDIC circuits
K1 hardware design experiments
K1 Loeffler algorithm
K1 structurally orthogonal scaled CORDIC-based approximations
K1 software JPEG codec
K1 multiplierless transforms
K1 coordinate rotation digital computer
K1 lifting-based BinDCT schemes
K1 field programmable gate array
K1 short-critical-path
K1 eight-point discrete cosine transform
DO https://doi.org/10.1049/iet-cds.2012.0233
UL https://digital-library.theiet.org/;jsessionid=1vnxe60677v94.x-iet-live-01content/journals/10.1049/iet-cds.2012.0233
LA English
SN 1751-858X
YR 2013
OL EN